Method for controlling connect and disconnect forces of a connector

ABSTRACT

A connector includes a housing having a bore with a housing groove disposed on an inside surface of the bore with a groove establishing a release angle between a housing groove bottom and a bore inside surface. A retainer defines a spring cavity between a retainer and the release angle and a circular radial canted coil spring is disposed in the spring cavity. A pin having a tapered end and a body diameter sized for sliding engagement with the bore is provided which includes a circumferential groove in the pin body for receiving the coil spring upon insertion of the pin into the bore. A circumferential groove includes a load angle for rotating the coil spring in an orientation in which the major spring axis is parallel to the release angle upon initial withdrawal of the pin from the bore. The coil is further compressed along the spring minor axis and expands radially upon continued withdrawal of the pin from the bore.

The present invention is generally related to connecting mechanisms andis more particularly related to a connector that requires low force toconnect and high force to disconnect.

Connectors have been used in a great variety of applications, see, forexample, U.S. Pat. Nos. 4,678,210, 4,763,683, 5,411,348 and 5,545,842.Each of the connectors referenced are directed to specific applications.

For example, U.S. Pat. No. 4,678,210, provides for a loading and lockingmechanism directed to engaging and interlocking lightweight, delicateand many times fragile cylindrical parts with one another and providesfor locking means for preventing separation of a first and secondcylindrical member.

U.S. Pat. No. 4,763,683 is directed to a breakaway coupling for acoaxial fuel supply hose and provides for inner-connecting valve bodies,which define a center fuel supply passage.

U.S. Pat. Nos. 5,411,348 and 0.5,545,842 are directed to mechanisms forconnecting and locking parts for effecting electromagnetic shielding,electrical conductivity, heat dissipation and environmental sealing.

The present invention provides for a connector utilizing a radial cantedcoil spring positioned within a housing groove in a manner forcontrolling connect and disconnect forces with a groove pin.

SUMMARY OF THE INVENTION

A connector in accordance with the present invention generally includesa housing having a bore with a groove disposed on an inside surface ofthe bore. The bore groove establishes a release angle between a housinggroove bottom and the bore inside surface.

A retainer is provided for defining a spring cavity between the retainerand the release angle and a circular radial canted coil spring isdisposed in the spring cavity. The coil spring includes a centerline, amajor and a minor axis, as hereinafter described.

A pin is provided having a tapered end and a body diameter sized forsliding engagement with the bore inside surface. A circumferentialgroove is formed in the pin body for receiving the coil spring uponinsertion of the pin into the bore.

The circumferential groove includes a load angle for rotating the coilspring in an orientation in which the spring major axis is parallel withthe release angle upon initial withdrawal of the pin from the bore.Continued withdrawal compresses the coil spring along the spring minoraxis and upon further withdrawal of the pin from the bore the springexpands radially.

More particularly, the load angle is disposed below a centerline of thecoil spring, should the load angle be above the centerline of the coilspring, disconnect would not be possible. This distinguishes the presentinvention from the hereinabove referenced prior art patents.

More particularly, the housing groove may include a coil groove stopdisposed between the release angle and the bore inside surface forlimiting axial movement of the coil spring upon withdrawal of the pinfrom the bore.

The release angle may be disposed at between about 5° and about 90° tothe centerline connector and is preferably disposed at between about 25°and about 65° to the connector centerline.

With the use of the stop means, hereinabove noted, the preferablerelease angle is between about 25° and about 30° to a centerline of theconnector.

Still more particularly, the coil spring may be initially disposedwithin the cavity with a major axis disposed within an included angle ofbetween about 30° and about 45°. In that regard, the coil spring may beinitially disposed in the cavity in a convex orientation or in a concaveorientation.

In all of the embodiments of the present invention, the load angle maybe disposed at an angle of between about 50 and about 90° with theconnector centerline and preferably at about 40° to the connectorcenterline.

Preferably, the coil spring has an inside diameter smaller than the pinbody diameter, so that a force is provided which urges the coil springtoward the inside diameter of the pin groove. This facilitates insertionof the pin into the spring. In addition, preferably, the load anglemeans is greater than the release angle by at least 10.

Further, control of the ratio of connect to disconnect forces isprovided by a spring having a ratio of coil width to coil height ofbetween about 1 to about 1.5, preferably, between about 1 to about 1.04.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will be betterunderstood by the following description when considered in conjunctionwith the accompanying drawings in which:

FIG. 1 is a side view, in partial cross section, of a connector inaccordance with the present invention generally showing a housing with abore and groove therein, a retainer for defining a spring cavity, acircular radial canted coil spring disposed in the cavity and a pinhaving a tapered end with a body diameter sized for sliding engagementwith the bore inside surface;

FIGS. 2-3 are front and right hand side views, respectively, of a radialcanted coil spring for use in the present invention;

FIGS. 4-8 are similar to FIG. 1 showing stepwise insertion, or connect,and withdrawal, or disconnect, of the pin from the housing utilizing arelease angle of 23° and further showing stop means disposed between therelease angle and a bore inside surface for limiting axial movement ofthe coil upon withdrawal of the pin from the bore, the circumferentialpin groove including a load angle for rotating the coil spring to anorientation in which the spring major axis is parallel to the releaseangle upon initial withdrawal of the pin from the bore;

FIG. 9 is an alternative embodiment to the present invention in whichthe radial spring is initially disposed in the cavity in a concaveorientation with an included angle of 30°

FIG. 10 is a view of another embodiment to the present invention inwhich the radial spring is initially disposed within the cavity in aconvex orientation having an included angle of about 30°;

FIGS. 11-16 are similar to the embodiment shown in FIGS. 1 and 4-8showing stepwise positions of the pin, spring and housing during connectand disconnect with a release angle of about 33°;

FIGS. 17-22 are similar to the embodiment shown in FIGS. 11-16 with thespring being initially disposed in the cavity in a concave orientation;

FIGS. 23-28 are similar to the embodiment shown in FIGS. 11-16 with thespring initially disposed in the cavity in a convex orientation;

FIGS. 29-34 are similar to FIGS. 1 and 3-8 showing connect anddisconnect steps with a release angle of about 45°;

FIG. 35 is a view similar to FIG. 17 with a release angle at 45°;

FIG. 36 is a connector similar to that shown in FIG. 10 with a releaseangle of 45°;

FIGS. 37-38 shown an embodiment in which the release angle is 65°;

FIGS. 39-40 are similar to the embodiment shown in FIGS. 37-38 utilizinga radial spring in a concave orientation with an included angle at 45°and a release angle of 65°; and

FIGS. 41-45 shows stepwise connect and disconnect sequential movement ofthe pin in housing utilizing a radial spring in a convex orientationwith an included angle of 45° and a release angle of 65°.

DETAILED DESCRIPTION

With reference to FIG. 1, there is shown a connector 10, which includesa housing 12 having a bore 14, having a groove 16 disposed on an insidesurface 18. The groove 16 establishes a release angle, or surface, 22between a housing groove bottom 24 and the bore inside surface 18.

A retainer 28 is provided, which defines a spring cavity 30 between theretainer 28 and the release angle surface 22.

A circular radial canted coil spring 32 is disposed in the spring cavity30 and a pin 34 having a tapered end 36 includes a body 38 having adiameter sized for sliding engagement with the bore inside surface 18.

The pin 34 includes a circumferential pin groove 48 having a load angle,or surface, 46, which provides a means for rotating the spring 32 to anorientation in which a spring major axis 54, see FIGS. 2 and 3, isparallel with the release angle 22 upon initial withdrawal of the pin 34from the bore 14, as will be hereinafter discussed in greater detail.

Further withdrawal of the pin 34 from the bore 14 compresses the coilspring 32 along a spring minor axis 56 (again, see FIGS. 2-3) andexpands the spring 32 radially upon continued withdrawal of the pin 34from the bore 14 as also discussed hereinafter.

With specific referenced to FIGS. 2 and 3, there is shown the circularradial canted coil spring 32 having a centerline 60 and a turn angle A.The turn angle A is the angle between the centerline 60 of the spring 32and a centerline of the coils 62. Such springs 32 are described in U.S.Pat. Nos. 5,139,243, 5,108,076 and 4,893,795. These patents are to beincorporated herewith in their entirety by this specific referencethereto for describing the types of radial springs suitable for thepresent invention.

This spring 32 includes an inside diameter, D, which is smaller than thepin groove 48 diameter in order that the spring 32 is forced toward apin groove bottom, or inside diameter, 66.

As shown in FIGS. 1 and 4-8, the release angle 22 is disposed at about23° to a centerline 70 of the connector 10. It should be appreciate thatthis release angle may be disposed at between about 5° and 90° with thecenterline 70 of the connector 10 in order to control, connect anddisconnect forces, as hereinafter described.

With reference again to FIG. 1, the load angle, L, may be disposed at anangle of between about 50 and about 90° to the connector centerline 70,with about 40° being shown in FIGS. 1-8. This load angle surfacecontributes to the control of connects/release force ratios, as will behereinafter discussed in greater detail.

As shown in FIG. 9, a radial spring 72 may be initially disposed in thecavity 30 in a concave orientation with an included angle of betweenabout 30° and about 45°, 30° being shown. In this arrangement, a majoraxis 76 is initially oriented in a direction toward a connect directionof the pin 34, as shown by the arrow 78.

With reference to FIG. 10, there is shown a spring 82 disposed in aconvex orientation within the cavity 30 having an included angle ofbetween about 30° and about 45°, 30° being shown. In this arrangement, acoil major axis 84 is oriented against an insertion direction of the pin34, as indicated by the arrow 86. It should be appreciated that commonreference numbers used throughout the specification and all of thedrawings represent identical or substantially similar components.

FIGS. 11-16 are similar to FIGS. 1 and 4-8 with a release angle of about33°. Similarly, FIGS. 17-22 include a release angle at 33° utilizing theconcave spring 72 and FIGS. 23-28 represent sequential connect anddisconnect steps utilizing a convex spring 82 with a release angle ofabout 33°.

FIGS. 29-34 are similar to FIGS. 1 and 4-8 with a release angle at 45°.FIG. 35 is similar to FIG. 29 utilizing a concave spring 72 and FIG. 36utilizing the convex spring 82 sequential connect/disconnect steps arerepresented in FIGS. 30-34.

FIGS. 37 and 38 are similar to FIG. 1, with a release angle of 65° witha corresponding concave spring 72 and convex spring 82 being shown inFIGS. 39 and 40.

FIGS. 41-45 shows the convex spring 82 with sequential connect anddisconnect steps with a release angle of 65°.

Variation of the load angle 46 to the release angle 22 affects the forcerequired to disconnect. The larger the release angle 22, the higher theforce to disconnect. The larger the load angle 46 the greater the forcerequired to disconnect. The greater the release angle 22 the greater thecoiled 62 reflection and the greater the force required to disconnect.

As hereinabove noted, the closer the radial centerline 70 of the spring32 to a load point 90 at the intersection of the pin body 38 with theload angle surface 46 (see FIGS. 1) the higher the disconnect forcepreparing in mind. However, if the load point 90 is above the centerline70 disconnect is not possible.

As shown in FIG. 1, the radial spring 32 has a 0° turn angle that is amajor axis 94 (see FIG. 1) is parallel with the connector centerline 70.The concave springs 72 have an included angle of between 1° and 89°included angle and the convex spring 82 has a turn angle of betweenabout 10 and 89° included angle, with 30° being shown in the FIGS. 17-22and 23-28 respectively.

Concave springs 72 have the advantage of reduced force during initialconnection when the concave angle is the same as the entry angle B, seeFIGS. 1 and 9 of the pin 34 because minimum force is require to turn thespring 72 during connection. If the angles of the springs 32, 82 and theentry angle B are different the tapered end 36 of the pin 34 must turnthe spring 32, 82 so that the major axis 94, 84 is parallel to the entryangle B of the tapered end 36 of the pin 34. The higher the variationthat exists between the entry angle B of the tapered end 32 of the pin34 and the turn angle of the spring the higher the force will berequired to connect.

As shown in FIGS. 1 and 4-8, the radial spring 32 has a major axis 94,which is parallel to the centerline 70, 60 of the spring 32, see FIGS.2-3. This type of spring 32 is desirable when the pin 34 has no chamfer,or tapered end, not shown.

In this case, the pin 32 outside diameter at entry will be parallel tothe major axis of coil since the inside diameter of the spring 32 isgenerally smaller than the pin body outside diameter 38. A tapered end,or chamfer, 36 is desirable for facilitating assembly. The tapered end36 reduces the force required to connect, which is important since anobjective of the present invention is to maximize the ratio ofdisconnect to connect force.

The concave spring 72 has the advantage that the tapered end 36 of thepin 34 at the entry angle can be made parallel to the concave angle. Inthis manner, the initial force required to connect is minimized bymaking the spring concave angle the same as the tapered end 36.

The convex spring 82 requires substantially greater force at entrybecause it will be necessary to turn this spring 82 to the position ofthe entry angle of the tapered end 36 of the pin 34. Thus, the convexspring 82 is desirable and applications for a high entry force isdesirable.

When connection takes place, the spring 32, 72, 82 positions itself atthe normal or initial position at the bottom 66 of the pin groove 48.The force required to disconnect the connector 10 varies depending uponthe type of spring 32, 72, 82 utilized be it the radial 32, radioconcave 72 or radio convex 82 with the concave spring 72 requiring moreforce to disconnect than the radial spring 32 and convex spring 82. Thereason for this force difference is due to the fact that the spring 32,72, 82 must position itself with the major axis 76, 84, 94 of the coilparallel to the release angle surface 22 in the housing 12, and thatrequires turning of the spring 32, 72, 82.

The concave spring 72 requires greater degree of turning of the coil inthe convex spring 82 and the more turning the spring 72, 82, the morestresses are parted to the spring causing greater force at disconnect.For these reasons, the spring 32, 72, 82 that requires minimum amount ofturning results in minimum disconnect force and maximum turning resultsand maximum disconnect force. The concave spring 72 offers greatervariation between disconnect and connect ratio because it requires lessforce to connect and greater forces to disconnect. When this feature isdesirable to concave spring 72 has significant advantage.

In general, there are four main factors that effect the selection of thespring for maximum connect or disconnect ratio. They are:

-   -   1. A connector whose entry angle is parallel to the entry angle        of the spring.    -   2. A coil that when deflected radially during the connecting        process has the minimum amount of frictional force. A concave        spring will have less frictional force.    -   3. A spring that when it is in the connect position will assume        a turn angle that will require maximum turning, thus creating        greater stresses on the spring and upon deflecting the        disconnect will create a higher force.    -   4. A spring when deflected at disconnect will develop a higher        force by varying the release angle. The higher the release        angle, the higher the amount of spring deflection and the higher        the force developed at disconnect.

In addition to the type of spring used, the many factors that willaffect the disconnect force.

-   -   1. The larger the release angle of the housing, the greater the        force required to disconnect.    -   2. The larger the load angle, the greater the force required to        disconnect.    -   3. The larger wire diameter of the spring coil, the greater the        force developed and the higher the force required to disconnect.    -   4. The smaller the ratio of the coil width to the coil height,        the rounder the cross section of the coil will be and the higher        the force to disconnect. The typical desirable ratio to develop        higher force would be 1 to 1.04.    -   5. The smaller the back angle of the coil, the higher the force        required to disconnect.    -   6. The smaller the front angle of the coil, the higher the force        required to disconnect.    -   7. The relationship between the centerline of the spring coil in        a connect position to the diameter of the pin at the load point.        The shorter the radial distance between the centerline of the        coil and the load point, the greater the axial force developed        at disconnect and the greater the force required to disconnect.    -   8. The higher the modulus of elasticity of the wire, the higher        the force to disconnect. Therefore, the selection of the spring        material becomes a very important factor in maximizing the ratio        of disconnect to connect.    -   9. The relationship between the load angle and the release        angle. The load angle must always be larger than the release        angle. The smaller the difference between the two, the greater        the force required to disconnect. For most applications, a        variation between the two of 70 appears to work satisfactorily.    -   10. The force required to stretch the spring during connection.        The higher the force, the lower the ratio of disconnect to        connect.    -   11. For this type of application, a spring force that increases        with deflection is highly desirable. This characteristic can be        achieved in a canted coil spring by controlling the ratio of the        coil height to wire diameter. The smaller the ratio, the higher        the force as a function of spring deflection.

With the present invention, the ratio of disconnect force to connectforce may be as high as 30 to 1. FIGS. 1 and 4-8 illustrate sequentialposition of the pin 34 and housing 12 utilizing a release angle 22 ofthe 23°. FIGS. 11-16 illustrate the connect disconnect steps utilizing arelease angle of 33° and FIGS. 29-34 show the connect/disconnect stepswith a release angle at 45°. These figures show a comparison between theeffect that the release angle 22 has on the axial play and deflection ofthe spring 32. As hereinabove noted, the smaller the release angle 22the lower the force developed. The larger the release angle 22 thehigher the deflection and the higher the force developed to disconnect.

It should be appreciate that the actual play of the pin 34 varies withthe release angle 22. By way of specific example, at small angles, thatis 23° and 33° the axial play is approximately the same at about 0.007inches. As a release angle 22 increases to 45° the axial play decreasesto 0.004 inches with the same dimensions. See FIGS. 29-36. The axialdeflection is 0. All of the springs 22, 72, 82 (see FIGS. 37-45).

Although there has been hereinabove described a specific connector withradial spring in accordance with the present invention for the purposeof illustrating the manner in which the invention may be used toadvantage, it should be appreciated that the invention is not limitedthereto. That is, the present invention may suitably comprise, consistof, or consist essentially of the recited elements. Further, theinvention illustratively disclosed herein suitably may be practiced inthe absence of any element, which is not specifically disclose herein.Accordingly, any and all modifications, variations or equivalentarrangements which may occur to those skilled in the art, should beconsidered to be within the scope of the present invention as defined inthe appended claims.

1-17. (canceled)
 18. A method for controlling connect and disconnect forces of a connector the connection comprising: a housing having a bore with a housing groove disposed on an inside surface of said bore, said groove establishing a release angle between a housing groove bottom and the bore inside surface; a retainer for defining a spring cavity between the retainer and said release angle; a circular radial canted coil spring disposed in said spring cavity, the coil spring having a major and a minor axis; a pin having a tapered end and a body diameter sized for sliding engagement with the bore inside surface and having a circumferential groove in the pin body for receiving the coil spring upon insertion of the pin into the bore, said circumferential groove having load angle means for rotating the coil spring to an orientation in which the spring major axis is parallel with said release angle upon initial withdrawal of said pin from said bore and compressing the coil spring along the spring minor axis and expands the spring radially upon continued withdrawal of said pin from said bore, said retainer being positioned for engaging the spring upon insertion of the pin into the bore; and said method comprising using a concave radial canted coil spring to minimize connect forces.
 19. The method according to claim 18 further comprising increasing the release angle to increase disconnect forces.
 20. The method according to claim 18 further comprising increase the load angle to increase disconnect forces.
 21. The method according to claim 18 further comprising decreasing a spring coil width to coil height ratio to below 1.04.
 22. The method according to claim 18 further comprising decreasing a radial distance between a spring centerline and the load point.
 23. The method according to claim 18 decreasing a difference between the load angle and the release angle. 